Drain for breather type roofs



Oct. 9, 1934. .J, H. WIGGINS DRAIN FOR BREATHER TYPE ROOFS Filed June27. 1932 FIGI.

FIGZ.

INVENTOR Jo /V/1.Wl 6/ 5 W Patented Oct. 9, 1934 DRAIN FOR BREATHER TYPEROOFS John H. Wiggins, Tulsa, Okla.

Application June 27, 1932, Serial No. 619,378

2 Claims.

This invention relates to a drain for conducting rain or snow water fromthe top side of tank roofs of the type commonly referred to as breatherroofs, which, as is well known, usually consist 5 of a metallicdiaphragm constructed in such a manner that in the normal use of thetank the central portion of the diaphragm flexes upwardly anddownwardly, due to variations in the internal pressure of the tank.

One object of my invention is to provide a relatively compact metallicdrain for a breather type roof that will not interfere with the flexingof the roof, and in turn, will not be injuriously affected by theflexing of the roof.

Another object is to provide an eflicient drain for breather type roofs,that is easy to install and of such construction or design that no partsof same will contact with or strike against the stationary supportingstructure on the inside of the tank, used to sustain the roof in itsdownwardly deflected condition.

Another object is to provide a drain for breather type roots, which isof such construction or design that no portion of same is located veryfar below the top of the tank, with the result that in case of anyleakage, there is not a high liquid head that will cause rapid leakage.

And still another object is to provide a storage tank having a breatherroof and a drain for said roof that can be removed without taking thetank out of service and without the necessity of drawing off liquid fromthe tank to lower the level of the liquid.

To this end I have devised a drain which, briefly described, consists ofa metallic conduit arranged in close proximity to the top of the tankand extending inwardly from the tank side wall, preferably for only aportion of the radius of the roof, and means for attaching or combiningsaid conduit with the roof and with the tank side wall in such a waythat said conduit is capable of moving bodily sufficiently, when theroof flexes upwardly or downwardly, to not interfere with the flexing ormovement of the roof, and in turn, not be injuriously affected by themovement of the roof. Said conduit is preferably located in the spacebetween the underside of the roof and the normal high level of theliquid in the tank, and it is so arranged that it will not contact withor strike against the roof beams or other supporting structure inside ofthe tank on which the roof rests whenthe roof is inits downwardly flexedcondition. The method or particular means used to combine said conduitwith the roof and side wall is immaterial, and may be varied in numerousways Without departing from the spirit of my invention, but I prefer topivotally connect the inner end of said conduit to a sump on the rooflocated at a point remote from the center of the roof and attach theopposite end of said conduit to a jointed tubular structure sustained orcarried by the tank side wall and constructed in such a manner that itforms a continuation of said condiut which is capable of moving in sucha way as to permit said conduit to move bodily in a radial directionwhen the central portion of the roof flexes upwardly and downwardly,whereby the drain will not interfere with the flexing of the roof andthe drain, in turn, will not be injuriously affected by the flexing ofthe roof.

Figure 1 of the drawing is a fragmentary vertical transverse sectionalview of a breather type roof equipped with a drain constructed inaccordance with my invention.

Figure 2 is an enlarged fragmentary vertical transverse sectional viewof the roof and the drain.

Figure 3 is a top plan view of the drain with the rcof broken away so asto show the arrangement of the drain with relation to the roof support.

Figure 4 is a vertical sectional view, taken on the line 4-4 of Figure3, looking in the direction indicated by the arrows.

Figure 5 is a vertical sectional view, taken on the line 5-5 of Figure3, looking in the direction indicated by the arrows; and

Figure 6 is a top plan view of the sump on the roof to which the innerend of the drain is attached.

In the accompanying drawing, which illustrates the preferred form of myinvention, A designates the side wall of a liquid storage tank, and Bdesignates a breather type roof for said tank formed usually from aflexible metallic diaphragm whose peripheral portion is attached to thetank side wall and whose central portion is capable of flexing upwardlyand downwardly to vary the volume of the internal space of the tanklocated above the level of the liquid in the tank. When the roof B is inits downwardly flexed condition, the roof rests upon a stationarysupporting structure which is usually composed of a number ofradially-disposed roof beams 1 that project inwardly from the side wallof the tank and whose inner ends rest upon or are connected to anannular framing 2, which, in turn, is supported by posts or uprights 3,as shown in Figures 1 and 2. The conventional breather roof, in itsdownwardly flexed condition, comprises a flat central portion thatconstitutes from one-half to two-thirds of the radius of the roof, andin the normal use of the tank, the variation in the internal pressure ofthe tank causes the central portion of the roof to rise and fall or toflex upwardly and downwardly.

My invention consists of a drain for a tank roof of the general typereferred to, that is located on the underside of the roof in the spacebetween the roof and the normal high level of the liquid in the tank,and which has provision for permitting the drain as an entirety to movesumciently to adapt itself to the flexing of the roof, or in otherwords, to not interfere with the flexing of the roof, or in turn, beinjuriously affected by the flexing of the roof. Said drain extendsinwardly only a portion of the radius of the roof, and it is arrangedbeyond or outside of the annular framing 2 of the roof supportingstructure, preferably between two of the radiallydisposed roof beams 1.It is made up of metallic parts, and in the preferred form of myinvention herein illustrated comprises a conduit or pipe 4, in hydraulicgradient, that leads from a sump 5 on the roof to a jointed tubularstructure carried by the side wall A of the tank and constructed so asto form an outlet for the conduit 4 through which water escapes from thesump 5 and is discharged at a point outside of the tank. The sump 5 isherein illustrated as consisting of a cast iron box connected byfastening devices 6 to a plate 7 that is welded to the roof B, and thepipe or conduit 4 previously referred to has its inner end pivotallyconnected to the sump 5 by means of a conventional street L 8, one ofwhose legs or portions is disposed horizontally and screwed into aninternally-threaded hole formed in one of the vertical side walls of themetal box that constitutes the sump 5.

The jointed tubular structure, previously referred to, is connected tothe opposite end of the conduit 4, and in the form of my inventionherein illustrated comprises a horizontally-disposed stationary pipe 9mounted on and projecting inwardly from the tank side wall A, ahorizontally-disposed movable pipe 10 arranged between the stationarypipe 9 and the outer end of the conduit 4, and pivotal joints orconnections between said parts 9, 10 and 4 constructed in such a way asto permit the conduit 4 to move bodily radially with respect to the tankside wall when the roof B flexes upwardly and downwardly. One of thepivotal connections or joints just referred to is formed preferably by astreet L 11 on the conduit 4 that is screwed into an L 12 carried by themovable pipe 10, and the other pivotal con-,

nection or joint is preferably formed by a street L 13 on the oppositeend of the pipe 10 that is screwed into an L 14 carried by thestationary pipe 9. Usually, the pipe 10 will be composed of two sectionsjoined together by a pipe union or equivalent means 15 that willfacilitate the assembly or disassembly of the parts constituting thedrain. A bracket 16 that projects inwardly from the tank side wallserves as a support for the horizontally movable pipe 10, and the tankside wall is provided with a removable hand hole plate 17' held inposition by fastening devices 17a, that provides access to the drain. Inorder that the pivotal connection between the inner end of the conduit 4and the sump 5 may be kept thoroughly lubricated, the part on the sidewall of the sump into which the street L 8 is screwed, is provided witha lubricant duct 18 (see Figure 5) that is adapted to be filled withgrease or some other suitable lubricating medium, said duct beingnormally closed by a removable plug 19.

In a drain of the construction above described the conduit 4 will assumedifferent angular positions with relation to the roof and will moveradially with respect to the side wall of the tank when the roof flexesupwardly and downwardly, due to the fact that the inner end of theconduit 4 is pivotally connected to the sump 5 and the outer end of saidconduit is attached to a jointed structure on the side wall thatcomprises two angularly-disposed joints or pivots, which form in effecta universal connection between the conduit 4 and the stationary pipe 9on the tank side wall that constitutes the discharge portion of thedrain. Accordingly, such a drain will not interfere with the flexing ofthe roof, and in turn, the drain will not be injuriously affected orsubjected to strains tending to cause it to leak, by the movement orflexing of the roof. As the drain is'located outside of or beyond theannular-framing 2 of the roof supporting means, between two of the roofrafters, 1, it will not contact with or strike against the roofsupporting means when the roof flexes upwardly anddownwardly. The drainis short and compact and extends inwardly from the tank side wall only aportion of the radius of the roof, and as no portion of same is locatedvery far below the top of the tank, there is not a high liquid head thatwill cause rapid leakage, in the event a slight leak develops in thedrain. In such a drain the leakage would normally be only vapor, whichwould do very little harm. Moreover, as the drain is in hydraulicgradient, water cannot collect and freeze in same and cause the drain torupture. In addition to the desirable characteristics above pointed out,my drain has the added advantage of being capable of being removed fromthe tank for cleaning, inspection or repair, without taking the tank outof service and without the necessity of drawing 01f liquid from the tankso as to lower the level of the liquid. This, of course, results fromthe fact that the drain is located above the normal high level of theliquid in the tank, and is detachably connected to the roof and to thetank side wall in such way that after the drain has been disconnectedfrom said parts, the drain can be bodily removed from the tank throughthe opening in the tank side wall that is normally closed by theremovable hand hole closure 17. To remove the drain the sump 5 isdetached from the roof and the closure 17 is detached from the tank sidewall. A rope is then tied to some part of the drain, and the entiredrain is then pulled outwardly through the hand hole opening in the tankside wall that is normally closed by the plate 17.

Having thus described my invention, what I claim and desire to secure byLetters Patentis: 1. A storage tank provided with a side wall, abreather type roof for said tank, a, sump on said roof located at apoint between the side wall and the center of the roof, a metal drainpipe on the underside of the roof pivotally attached at its inner end tosaid sump and extending substantially radially from same towards saidside wall, and a jointed metallic structure carried by said side walland combined with said drain pipe so as to form a continuation of same,said jointed structure having provision for permitting the drain pipe tomove substantially radially with respect to said side wall when the roofflexes.

2. A tank of the kind described in claim 1, in which the tank side wallis provided adjacent its upper edge with an opening through which saiddrain pipe and jointed structure can be withdrawn from the interior ofthe tank, and a closure for said opening.

JOHN H. WIGGINS.

